The shortcomings of the prior coffee roasting systems utilizing a fluidized bed created by a flared chamber have been eliminated by the use of a rotating fluidized bed as described in U.S. Pat. No. 4,494,314 for "Coffee Roaster" and U.S. Pat. No. 5,359,788 for "Coffee Roaster" issued to Harold Gell on Jan. 22, 1985 and Nov. 1, 1994 respectively. With the advent of rotating fluidized bed applications to coffee roaster technology and transparent upper oven chambers which allow operators to monitor the roasting process, the problems involving the actual roasting technique have been solved. However, the different thermal expansion characteristics of the glass upper oven chamber and metal lower oven chamber results in a high failure rate of the glass chamber section and problems remain with respect to removing roasted coffee beans from the oven chamber, cleaning the oven chamber and manufacturing the oven chamber.